Computer technologies have developed for the presentation of three-dimensional virtual worlds to users of computing devices.
For example, a virtual world can be hosted on a set of server computers (e.g., secondlife.com). Client programs or viewers can be installed on user computers for connections to the server computers and for user participation in the virtual world. Users of a virtual world can be presented as the residents of the virtual world in the form of avatars. The resident avatars can travel in the three-dimensional virtual world, explore the three-dimensional virtual world, meet other resident avatars for virtual social activities, and communicate with each other via voice, instant messaging, text chart, local chat, and/or group chat. The avatars may build, create, shop and trade virtual objects and services with each other in the three-dimensional virtual world.
Avatars of a virtual world may take various forms, such as human, animal, vegetable, etc. In a virtual world, users may customize various aspects of their avatars and may choose to resemble the users themselves in appearance as they are in the real world. A user may have multiple avatars, but use only one avatar at a time for participation in the virtual world.
In a virtual world, a user of a client program or viewer of the virtual world can use conventional input devices to control the activities of the avatar that represents the user in the virtual world, such as keyboards and pointer control device (e.g., mouse, touch pad, track ball, joystick, and touch screen). The view of the virtual world as currently being seen by the avatar at its current position and orientation can be presented on a display device, such as a computer monitor, a display of a notebook computer, a touch screen of a mobile device.
Virtual reality headsets have been developed to provide an immersive experience of virtual reality. A virtual reality headset may have a stereoscopic head-mounted display to provide separate images for each eye of a user. A virtual reality headset may also be able to produce stereo sound, and generate user inputs via motion tracking sensors, such as gyroscopes, accelerometers, etc. Some virtual reality headsets also have eye tracking sensors and/or gaming controllers.
Eye tracking involves the measuring the point of the gaze or the motion of an eye of a user relative to the head of the user. For example, the eye position may be extracted from video images for the determination of the point of the gaze and the eye movements relative to the head.
There is a challenge to present eye movements of avatars in virtual world, especially when the user devices do not have eye tracking capabilities.